The invention relates to ski poles, and a main object of the invention is to make it possible with manufactured materials to make ski poles which are really well suited for race and cross-country skiing and hence can compare in this respect with the Ton-kin rods commonly used at present.
Whereas metal tube poles are dominating in alpine skiing, they have had no success as far as race and cross-country skiing is concerned. There are several reasons for this. An important reason is that metal poles have a much too quick rebound and therefore feel hard and in the long run are tiring for the arm and the hand. Besides, they cause uncomfortable chinking, so that they sound and sing just up into the ear for each step on icy snow.
Attempts have been made with glass-reinforced plastics as materials for ski poles, but here difficulties have been encountered with respect to combining light weight and correct resiliency on the one hand and satisfactory mechanical strength on the other.
Further, attempts have been made for improving the mechanical properties of metal poles by making the metal tube with a crosssection decreasing towards both ends from a thicker central portion, so as better to withstand buckling stresses while at the same time having somewhat more flexible end portions. However, this is by far not sufficient for eliminating the drawbacks set out above and, besides, entails the risk of breaking of the pole in the vicinity of the disc when it gets stuck in crust or packed snow.
The consequence has therefore been that the natural materials a bamboo and Ton-kin are still the dominating materials for poles for race and cross-country skiing. However, in view of the intensive expansion that is at present taking place in both these sport branches it cannot be expected that the supply of these materials will be sufficient for covering the demand in the long run, so that there exists a pronounced demand for finding satisfactory substitutes.